During endoscopic retrograde cholangiopancreatography (ERCP) procedures in which an extraction balloon is being used, a syringe is attached to the hub connected to the inflation lumen. This syringe is used to inflate the extraction balloon to the size necessary, as determined by the clinician, to remove the obstruction. The outer diameter of the inflated balloon typically corresponds with the inner diameter of the duct being swept. Because of the variation in the ductal anatomy, there is not a typical inner diameter for the ducts, for example the ducts within the biliary system, especially when the ducts are compromised with obstructions and strictures.
Currently, manufactures of extraction balloons provide syringes which enable the users to inflate the balloons to specific inflated diameters. Two methods of controlling the inflation volume are typically used. One method uses a hole drilled through the wall of the syringe at a precise location. The location of the hole only allows injection of a controlled volume of air into the balloon. The second method uses protrusions on the inside of the syringe barrel at a precise location to prevent the syringe plunger from travelling the full length of the syringe barrel so that a controlled volume of air is injected in to the balloon. Each type of syringe also includes markings along the syringe barrel to indicate where the plunger must be moved in order to obtain the labeled balloon inflation diameter.
The current syringe devices used for inflating the balloons include at most four predetermined markings. Size constraints on the markings, for example to provide clear visibility and variation in the location of the marking due to dimensional tolerances, limit the number of markings that can be provided as well as the accuracy of the markings on the syringe barrel.
What is needed in the art is a device and a method for allowing incremental inflation of a balloon to allow the clinician to size the balloon to the patient's specific anatomy, allow a greater number of accurate sizes and for repletion of inflation of the balloon to a specific outer diameter.